Photographic screening layer



' June 6, 1944. JELLEY r 2,350,764

PHOTOGRAPHIC SCREENING LAYER Filed Feb. 5, 1943 BLUE SENSITIVE EMULSION.

GELAT/N FILTER LAYER 0F METAL SALT 0F 05/? Z ONE OF D/H YDROX Y TARTAR/C A670.

v 6REEN SENSITIVE EMULSION.

GEL/IT/h LAYER.

RED SENS/Tl v5 EMULSION.

\SUPPORT.

A TTORNEYS sensitive element.

Patented June 6, 1944 rnoroemrmc SCREENING LAYER. Edwin E. Jelley and Paul w. Vlttum, Rochester,

alaiznors to Eastman Kodak Company,

N. Y., a' corporation oi New Jersey Application February 5, 1943, Serial No. 474,836

8 Claims.

This invention relates to photographic elements, and more particularly to such elements carrying screening material either in the emulsion layer or in a separate layer.

It is known that the amount of light which reaches a sensitive photographic element may be reduced or restricted to light oi a definite color by the use of screening layers coated over the Numerous screening materials have been proposed among which are Tartrazine, Naphthol Yellow. and Quinoline Yellow. These dyes have the undesirable property of desensitizing cyanine sensitized emulsions and, therefore, are unsuitable for incorporation in emulsions which have been color-sensitized by cyanine dyes. Certain dyes and filter materials hitherto used have the additional undesirable property of diil'using or wandering from the layer in which they are incorporated. When it is desirable to coat a layer of sensitive emulsion or plain gelatin containing a dye or screening material adjacent to another layer which is to contain either a definite dye or no dye at all, it is essential that there be no wandering of the dye from layer to layer during or after coating; and

the above formula wherein R is an aryl group as, for example, phenyl m-tolyl, p-carboxyl phenyl. p-nitrophenyl, 2,4-dinitrophenyl, p-(p-tert. butyl phenoxy) phenyl, naphthyl and substituted naphthyl, and M is either calcium, barium, strontium, or magnesium. These salts are removable from water-permeable layers in which they are incorporated, by means of alkaline photographic processing solutions.

For the carrier material for the filter layer. whether it be a, layer of a multilayer film or a layer such as a Wratten filter layer containing the above compound. may be used gelatin, cellulose esters and natural or synthetic resins. especially gelatin and water-permeable cellulose esters and resins where the layer must be permeable to alkaline photographic processing solutions in order to remove the metal salt from the layer after it has served its purpose in screening underlying sensitive layers.

The following table gives the colors of representative calcium salts of the compounds of our invention where R. in the above formula is a phenyl or substituted phenyl group.

when the layer in which the dye is incorporated 0010, is light sensitive. it is further essential that the dye does not desensitize the emulsion. The difmm 1 new, ficulties have been especially noticeable in yellow m-To yl Yellow-orange. dyessma t.....':

The principal object of'the present invention is Minion heii'iiiii Orange-led. to provide yellow filter materials which do not utylphmmpheny Yamw' wander from the layer in which they are incorporated, which do not desensitize light-sensitive photographic emulsions and have the desired spectral absorptions.

The objects of the invention are accomplished by dispersing a metal salt of an osazone derivative of dihydroxy tartaric acid in a layer oi a light-transmitting colloidal film-forming material.

The metal salts which our invention contemplates are those having the formula BNB-N=C-C0| \M a-Nn-N. -c0

The metal salts effective tor our NW have The preparation of salts of dihydroxy tartaric acid phenylosazone is described in Berichte der Deutschen Chem. Gesellschaft, vol. 20, 1887, pages 836-838. The preparation of salts of dihydroxy tartaric acid p-nitrophenyl osazone is described by Gnehm und Benda in Annalen der Chemie, vol. 299, 1898, pages 104-106. The m-tolyl, p-carboxyl phenyl, and 2,4-dinitrophenyl derivatives are prepared similarly using m-tolyl hydrazine, 'p-carboxyl phenyl hydrazine or 2,4-dinitro hydrazine respectively as the starting materials, in place of the phenyl hydra zine or p-nitrophenyl hydrazine used in the methods of the references. In preparing the -(p-tertiary butyl phenoxy) phenyl derivative, the corresponding hydrazine is employed. The

preparation or this hydrazine is described in British Patent 547,064.

The figure of the accompanying drawing shows described in gelatin solution and added to the blue-sensitive emulsion before coating, or if dein enlarged cross-sectional view a multilayer ously. Thus, during exposure of the sensitive photographic element the screening layer l4 p're-' vents passage of blue light from the top of the film to emulsion layers II and I3 which have inherent blue sensitivity in addition to conferred red and green sensitivity, respectively.

The following example is representative of the methods we use for incorporating the metal salts of the invention into layers of. colloidal filmforming materal.

A- solution is made of 0.8 gram of sodium dihydroxy tartrate phenyl osazone in 8 cc. of distilled water and 20 cc. of 95per cent ethyl alcohol. This is added to 50 cc. of a melted 10 per cent solution of de-ashed gelatin, and to this sired, the metal salt may be formed in the sensitive emulsion. I

Herein and in the appended claims where we state that our invention includes a photographic element comprising a support having thereon a plurality of light-sensitive emulsion layers sensitive to' difierent regions of the spectrum and a dispersion of a metal salt of formula given above, in colloidal film-forming material, we would have it understood that this includes incorporating mixture is added rapidly a solution of 0.8 grain of' calcium acetate. (monohydrate) in 16 cc. of

distilled water. The calcium osazone salt forms immediate and after coating the solution on a suitable surface and drying, there is obtained an intensely yellow colored layer in which the Metal salt is substantially non-diffusing. The calcium salt of dihydroxy tartaric acid phenyl osaz'one prepared in the manner described by re action of the sodium salt with a soluble calcium salt, was given the usual spectral absorption test and it was found that for wavelengths from about 520 mu to 460 mu the optical density varied from 0.36 to 2.4 falling ofi slightly at shorter wavelengths. The metal salts of the other aryl osazones have similar absorption curves but may be shifted depending on the color of the salt. We have compared the absorption curves of the compounds of the invention with those of other osazones and yellow filter materials and have found that our compounds absorb more com- 1 pletely in the blue region of the spectrum, as a result of which they are more satisfactory for use incolor photography. For example, the sodium salt of glucose phenyl osazone-p,p'-dicarboxylate has an absorption curve showing that the compoundhas substantially no absorption at wavelengths longer than 460 mu.

As is apparent, the above solution of the colored salt when employed for coating a filter layer such aslayer M of the drawing, is coated in a known manner on the green-sensitive emulsion layer it before coating the blue-sensitive emulsion layer l5 thereon. Other osazones and metal salts thereof contemplated by our invention are incorporated in'a layer of gelatin or similar material in a similar manner. In case it is desired to incorporate the filter material in one of the emulsion layers, such as the blue-sensitive emul-' """sibniayenli offlthe multilayer-film shown in the drawing, and this procedure and .the film ob-' tallied thereby is considered to be a part of our invention, the .metal salt is formed as abovethe metal-salt either in a-separate layer of a multilayer him or in one of the emulsion layers thereof.

It is to be understood that our invention may be used'in other ways not herein specifically mentionedand that we are to be limited only by V 7 the scope of the appended claims.

What we claim is:

1. -A photographic element comprising a support having thereon at least one light-sensitive emulsion layer, and a dispersion of a metal salt having the formula where R is an aryl group and M is a bivalent me al selected from the group consisting of calciuin, barium, strontium, and magnesium, in light-transmitting colloidal film-forming ma-- terial.

2. A photographic element comprising a support having thereon a plurality of light-sensitive emulsion layers sensitized to different regions of the spectrum,- and having over one of said emulsion layers a layer of a dispersion of a metal salt having the formula r R-NH-N=0-c'o,

cium, barium, strontium, and magnesium, in

light-transmitting colloidal film-forming material'.

3. A photographic element comprising a sup port having thereon a plurality of light-sensitive emulsion layers sensitive to different regions of the spectrum, and over one of, said emulsion layers a layer of a dispersion of a metal salt having the formula V vwhere R is an aryl group and M is barium, in light-transmitting colloidal film-forming .ma- 'terial.

4. A photographic element comprising support having thereon a plurality of light-sensitive emulsion layers sensitive to difierent-regions of the spectrum, and over one ofv 'sa'id emul-.

sion layers a layer of a' dispersion of a metal salt having theformula where R is aphenyl group and M is barium, in

hast-transmitting colloidal 1filmsfo'rming mate al.

5. photographic element comprising. a supsion layers a layer of a dispersion of a metal salthaving the formula RNlIN=C-CO:

where R is an aryl group and M is calcium,

in light-transmitting colloidal'film-forming material.

6. A photographic element comprising a sup-.

port having thereon a plurality of light-sensitive emulsion layers sensitive to diiferent regions of the spectrum, and over one of said emul-r sion layers a layer of a dispersion of a metal salt having the formula R-NHN=CCO:\

terial.

7. A'photographic element comprising a sup-V port having thereon a plurality of light-sensitive where R is a phenyl group and M is calcium, in light-transmitting colloidal film-forming maemulsion layers sensitive to diiferent regions of the spectrum, and over one of said emulsion layers a layer of a dispersion of a metal salt having the-formula RNHN=C-C0:\

RNHN= -co,, where R is an aryl group and M is magnesium, in light-transmitting colloidal film-forming material.

8. A photographic element comprising a support having thereon a; plurality of light-sensitive emulsion layers sensitive to diilerent regions of the spectrum, and over one of said emulsion layers a layer of a dispersion of a metal salt having the formula forming material.

Enwm E. JELLEY. PAUL w. VITTUM. 

